javascript 如何使用javascript获取输入字段的最大长度
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how to get the maxlength of an input field using javascript
提问by Tech Tech
I just wanted to know if we could get the maxlength of an input field from javascript
我只是想知道我们是否可以从 javascript 中获取输入字段的最大长度
<input type="password" id="password" maxlength="20" >
I tried this but it returns undefined
我试过了，但它返回 undefined
console.log(document.getElementById("password").maxlength);
回答by BlitZ
Use DOMElement::getAttribute()to obtain properties, that not listed in DOMElement, but existing in markup:
使用DOMElement::getAttribute()获得的属性，在一个DOMElement没有上市，但现有的标记：
var el = document.getElementById("password");
console.log(el.getAttribute('maxlength'));
回答by Tyler
document.getElementById("password").maxLength
To access it with Javascript you need an uppercase 'L'
要使用 Javascript 访问它，您需要一个大写的“L”
回答by Darren Sweeney
The accepted answer is actually wrong:
接受的答案实际上是错误的：
document.getElementById("password").maxLength
Will get you the maxLengthattribute e.g. maxLength="2", to get the value you must get just that:
将为您提供maxLength属性，例如maxLength="2"，要获得您必须获得的值：
document.getElementById("password").maxLength.value /* <-- note .value */
